1. Field of Invention
The present invention relates generally to shape grammars and, more particularly, to shape grammar systems and methods having parametric shape recognition.
2. Description of the Background
A shape grammar is a set of rules, based on shape, that is used to generatedesigns through rule applications. Rules take the form of a→b, where a and b both denote shapes. A rule is applicable if the left-hand shape, a, can be found in the design shape, denoted c. If the rule is applied, the left hand shape is subtracted from the design and the right-hand shape is added to the design, denoted c−τ(a)+τ(b), where shapes a and b undergo a transformation τ according to the transformation required to make shape a a subshape of shape c.
Shape grammars, having their roots in architecture literature, have recently found application in engineering, such as in the design of coffeemakers, lathe process plans, roof trusses, and microelectromechanical systems (MEMS) resonators. Shape grammars may be conceptualized of as a type of expert system based on geometry. Shape grammars, however, have succeeded in engineering applications where traditional expert systems have failed because of: (i) their direct handing of reasoning about geometry; (ii) their ability to operate on a parametric geometric representation; and (iii) their ability to support emergence of shape. These advantages presage a future in which shape grammars play an increasingly larger role in engineering design in comparison with the traditional expert systems.
In the past, however, shape grammars have been limited by the difficulty and time intensity in their implementations. Implementations have not allowed for general parametric shape recognition. Engineering shape grammars in particular have been restricted to limited, non-parametric shape recognition and often are hard-coded. These drawbacks minimize much of the beneficial potential of shape grammars.
Accordingly, there exists a need for a shape grammar system that uses shape recognition to provide, for example, an automated approach to product generation. There further exists a need for a shape grammar system in which engineering knowledge (geometry-based and otherwise) may be incorporated into implementation design rules in order to drive design exploration and the generation of designs toward a desired end.